The challenge of living with HIV involves long-term, complex self-management as well as consistent engagement in medical care. Engagement represents a patient's longitudinal commitment to care and permits People Living With HIV/AIDS (PLWHA) to take advantage of effective medical treatments. Yet too often patients new to care drop out of care or fail to maintain a regular appointment schedule. This proposal targets exploring and increasing acceptance of one's HIV status as a means to maximize engagement. Acceptance-based interventions target experiential avoidance, or an individual's attempts to avoid distressing internal and external experiences. For PLWHA, this might include anxiety about pending CD4 lab results or fear of stigmatization in one's community due to HIV diagnosis. Based on our prior work with PLWHA and acceptance-based interventions to keep patients in care in other populations, we suggest reductions in experiential avoidance will allow PLWHA to gain self-acceptance of serostatus and overcome engagement barriers. Our pilot development of a brief acceptance-based behavior therapy (ABBT) for antiretroviral adherence rooted in acceptance and commitment therapy (ACT), showed feasibility and acceptability in the primary care setting. However, this trial suggested that any improvement in medication adherence required prior engagement in medical services, the focus of the current proposal. Inevitably, life with HIV is stressful for a variety of reasons (e.g., medication side effects, shae, etc.); we suggest acceptance provides PLWHA with a framework to tolerate these stressors in the service of prioritizing a value-driven approach to engaging in medical care. The objectives of this R34 Clinical Trial Planning proposal are to (a) adapt ABBT to a two-session, individual-based acceptance-focused intervention to be delivered by case managers to diverse HIV+ primary care patients; (b) using an iterative open trial (n = 10), establish the structure, content acceptability, and feasibility of the adapted intervention; (c) conduct a randomized pilot trial ina sample of 40 ethnically/racially diverse patients who are new to primary care to establish the efficacy of ABBT in comparison to an treatment- as-usual (TAU) control condition, as preparation for an eventual large-scale (R01), adequately powered randomized clinical trial with the same research design; and, (d) examine preliminary psychometric properties of a novel measure of willingness to disclosure HIV status to non-sex partners. The clinical and public health impact of this project will be the development of a simple, low-cost, disseminable intervention for HIV patients new to care that enhances a patient's longitudinal commitment to care so s/he can obtain effective medical treatments that will prolong survival and improve quality of life.